The present invention relates to a cartridge and a method for preparing hot and cold beverages. The invention also concerns a method for dispensing said beverages.
There are two basic ways of preparing a coffee with a dispensing machine: by loading the loose ingredients, such as coffee beans or soluble ingredients, in the machine, in bulk form, ready to be dosed and in some cases (such as used coffee grounds) eventually disposed of, or by making use of a cartridge, i.e. a capsule or a pod, containing a preset amount of product. The product in the cartridge can be e.g. ground coffee or a leaf product, or a soluble ingredient, such as chocolate or cappuccino pre-mix.
The use of a cartridge has the advantage of sealing within the cartridge a coffee preparation (i.e. a ground or soluble product) in its best condition, with the maximum of its flavor and aroma being trapped in the cartridge or cartridge container.
A problem with cartridges is that of producing a good amount of cream.
Another problem is related to self-sealed cartridges. These cartridges are provided with sealing means to seal them without making use of a separate container. The sealing means have to effectively seal the cartridge content from air oxidation and at the same time they should be easily opened when the cartridge has to be used.
A further, constant problem, especially with those cartridges containing a ground or leaf product, is that of improving the brewing conditions so as to obtain the best possible beverage. This is particularly important with coffee. WO02/076270 discloses a system for the preparation of a beverage from a product contained in a disposable cartridge in combination with a collecting device having beverage collecting means designed to contain the cartridge, wherein at least one throttling arrangement is provided at the exit of the capsule to provide a controlled flow of beverage leaving the cartridge.
Although this system ensures superior mixing quality of the beverage, it is not very flexible.
WO2004/030499 in the name of the present Applicant, discloses an, apparatus and a method for the preparation of a beverage according to which a plunger perforates the bottom wall of the cartridge through an outlet opening and generates in correspondence to said opening a throttling element having specific dimensions that result in delivering the beverage product for at least 75% of the total dispensing time.
This capsule, as well as the previously mentioned ones, has the drawback of requiring a plunger, i.e. a perforating member to open the outlet opening in the bottom wall of the capsule.
In EP-A-1555218, the bottom wall of the capsule is provided with an area where the thickness is less than that of the remaining bottom wall; within this area a plurality of grooves are located: once the pressure inside the capsule has reached a sufficient value the thinner portion of the bottom wall breaks open along the grooves to provide outlet means for the beverage.
This embodiment has the drawback that the thinner portion including the grooves cannot guarantee a consistently reliable sealing of the capsule because the thinner portion and the weakening grooves can easily be partly broken when accidentally compressed.
Therefore, there is the need for an improved cartridge and for an improved method for preparing dispensing beverages in an easy, reliable, cost-effective way.